What is a treaty? ОА.
an informal agreement between two or more nations
B.
a formal agreement between two heads of state
O c.
an informal agreement between two heads of state
OD.
a formal agreement between two or more nations

OD.  A formal agreement between two or more nations.

Explanation:

A treaty is a formal agreement that is signed between two or more nations, according to the parties involved in that particular issue. It is a form or sign of a deal where the parties involved agreed to come to terms and signify the start of a peaceful co-operation between them.

The signing of treaties has been one of the most significant aspects of many events in the history of the world. Numerous wars and discords were solved with signing treaties, and also allows for peace and co-operation. These treaties contain pacts, deals, convention, and the participation of the involved parties in making peaceful efforts to progress, away from violent means.

Some of the more famous treaties in the world's history are The Treaty of Versailles in 1919, the Treaty of Paris in 1783, the Charter of the United Nations Organization in 1945, etc.  

- "the civil rights movements"

- "following the american civil war and abolition of slavery, the united states entered a period known as reconstruction, during which black americans continued to suffer from disenfranchisement, racial segregation, and economic oppression. beginning in the early 1950's, black americans launched a series of major campaigns of civil resistance, emphasizing the need for nonviolent protests and civil disobedience."

"such as the montgomery bus boycott of 1955-56, a campaign launched by rosa parks against the policy of racial segregation of the public transit system in alabama. “sit-ins” became popular across the american south, particularly in greensboro, north carolina, increase national sentiment."

- "the counterculture movement"

- "counterculture began to develop in the united states following the rise of conformity in american culture during the 1950s. by 1963, youth, particularly those of the white middle class, began rejecting the cultural standards and normality of their parents, opting for progressive attitudes instead. the movement gained momentum as the civil rights movement became increasingly successful and as the u.s. military intervention of vietnam began to take a negative turn."

"hippie counterculture moved further into popular culture following the summer of love in 1967 when thousands of people came together in the haight-ashbury neighborhood of san francisco. along with greenwich village in new york city, haight-ashbury became a hub for the counterculture movement."

in his book, the riddle of the rosetta stone, james giblin talks about how there was a young british polymath and physician named thomas young who made a lot of advances on the deciphering of the rosetta stone. he says that even though young made a lot of mistakes because he was working under false assumptions, he also made huge contributions like deciphering three out of the seven symbols (more than anyone else before him). young published his findings and continued his good work but he wasn't able to progress much further due to some unfavorable situations, he still laid the basis for many other scholars and of course for the man who has been generally known to have deciphered it, jean-françois champollion